Textile fibre drafting mechanisms

ABSTRACT

A FIBRE GUIDE IMMEDIATELY PRECEDES THE INTAKE OF A TEXTILE FIBRE DRAFTING MECHANISM AND PROVIDES A CONFINED PASSAGE THROUGH WHICH FIBRE IS FED TO SAID INTAKE AND FROM WHICH FIBRE IS PAID OUT UNDER TENSION, THE GUIDE HAVING FIBRE GUIDE SURFACES THAT MOVE ALONG WITH THE FIBRE CONFINED THEREBETWEEN.

Feb. 16, 1971 J, NOGUERA 3,562,869

TEXTILE FIBRE DRAFTING MECHANISMS Filed Aug. 2, 1968 United StatesPatent Office 3,562,869 Patented Feb. 16, 1971 3,562,869 TEXTILE FIBREDRAFTING MECHANISMS Joseph Noguera, London, England, assignor toCasablancas Limited, Manchester, England, a British com- Filed Aug. 2,1968, Ser. No. 749,789 Claims priority, application Great Britain, Aug.3, 1967, 35,671/ 67 Int. Cl. D01h 5/72 US. Cl. 19-288 11 Claims ABSTRACTOF THE DISCLOSURE A fibre guide immediately precedes the intake of atextile fibre drafting mechanism and provides a confined passage throughwhich fibre is fed to said intake and from which fibre is paid out undertension, the guide having fibre guide surfaces that move along with thefibre confined therebetween.

This invention relates to textile fibre drafting mechanisms forpreparatory or spinning machines and is concerned with facilitating theefficient guiding of textile fibres into the intake in such a mechanism.

As is well known, textile fibres delivered to drafting mechanisms ofspinning or preparatory machines may be in the form of coiled sliveraccommodated within a container, or in the form of twisted roving woundon to a bobbin. In either case, it is usual practice to provide someform of fork or funnel which is situated in front of a nip of a firstpair of drafting rollers to which the sliver or roving is to bedelivered and which serves to guide the sliver or roving into theaforesaid nip. Such forks or funnels, commonly known as sliver or rovingguides, can be of various shapes and differ from one another mainly intheir length and sectional area or aperture size.

In the majority of cases, a relatively long guide with an aperturehaving a relatively small cross-sectional area is preferred for optimumpresentation of the fibres to the drafting mechanism. Unfortunately,however, there are severe limitations upon length and aperture size ofthe guide arising from various causes. Not least among these causes isthat, as a guide acts more tightly upon the sliver or roving passingthrough it, there is an increased tendency to cause the leading ends ofthe outer fibres to fold backwards making so-called fibre hooks which isa very troublesome factor in drafting. In addition, the action of atight guide upon a roving obstructs the free passage of the rovingtwist, with the result that extra twist accumulates behind the guideuntil it eventually passes through the guide. This means that, in suchcases, there will be lengths of under-twisted roving fed into thedrafting mechanism followed by lengths of over-twisted roving. All thisis again disadvantageous from the point of view of efficient draftingbecause the drafting mechanism is alternately presented with a soft andthen with an unyielding formation of fibres. Yet another disadvantage oftight guides is that the resistance to be overcome in pulling the fibresthrough the guide varies with the inevitable irregularities of thesliver or roving and, in consequence, there is a risk of stretching andthereby causing further irregularities.

As distinct from the guides which are too tight or act too strongly uponfibre strands passing therethrough, wider or looser guides have theserious disadvantage of not presenting the fibres to the followingdrafting mechanism in a sufficiently straightened and well orientedmanner. Looser guides also have the disadvantage of not securing auniform feed since, when the roving or silver happens to be somewhattaut and straight or well directed,

it will be fed into the following drafting mechanism at a slower ratethan when it hapeens to be slack or on a bias.

A main object of the present invention is to obviate the variousdisadvantages and drawbacks of the known sliver or roving guides.

Accordingly, the invention provides a method of guiding textile fibresinto the intake of a drafting mechanism wherein the fibres approachingsaid intake are confined by guide means which immediately precede saidintake and from which the fibres are paid out to the intake undertension, said guide means being moved along with the confined fibres.

According to a further aspect, the invention provides a textile fibredrafting mechanism wherein a roving or sliver guide immediatelypreceding the intake of the mechanism has co-operating guide surfaceswhich provide therebetween a confined passage through which the sliveror roving is fed to said intake and from which the sliver or roving ispaid out under tension, said guide surfaces being arranged to move alongwith the sliver or roving confined therebetween.

For a better understanding of the present invention and to show how thesame may be carried into effect ref erence will now be made, by way ofexample, to the accompanying drawings, in which:

FIG. 1 is a diagrammatic side view of a first form of roving or sliverguide shown disposed for guiding roving or sliver to a pair ofco-operating drafting rollers,

FIG. 2 is a plan view from above of the guide and drafting rollers shownin FIG. 1,

FIG. 3 is a side view, taken in the direction of arrow III of FIG. 1, ofthe guide of FIG. 1,

FIG. 4 is a diagrammatic plan view from above of a second form of rovingor sliver guide shown disposed for guiding roving or sliver to a pair ofco-operating drafting rollers,

FIG. 5 is a diagrammatic side view of the guide and drafting rollersshown in FIG. 4,

FIG. 6 is a diagrammatic plan view from above of a first modified formof the guide of FIGS. 4 and 5, and

FIG. 7 is a diagrammatic plan view from above of a second modified formof the guide of FIGS. 4 and 5.

The various forms of roving or sliver guide shown in the figure are foruse with a conventional textile fibre roller drafting mechanism composedof a number of consecutive pairs of co-operating drafting rollers.Sliver or roving to be drafted is fed to the intake nip between thefirst pair of drafting rollers of the mechanism from a container orbobbin as the case may be, the sliver or roving being guided into thenip through a so-called sliver or roving guide. Each such guide shown inthe figures is arranged to exert a preferably yielding confining actionon the fibre strands forming the roving or sliver, approaching theintake roller nip and right up to a delivery point which closelyprecedes the nip. In this way, a maximum control can be exerted on thefibres passing through the guide and it is possible to ensure a veryhigh degree of accuracy both in orientation and tautness of the fibresdelivered to the nip. At the same time the guide surfaces which actuallyexert the confining action on the fibres are arranged to move with thefibres so that any twist which may be in the fibres entering the guideremains substantially unchanged when the fibres are paid out at thedelivery point. Furthermore the leading fibre ends will have little orno tendency to form fibre hooks. In this way an extremely regularpresentation of the fibres to the intake nip of the drafting mechanismcan be achieved since the right degree of control can be applied whilethe risk of producing twist or other irregularities is minimised.

The first form of roving or sliver guide 1 shown in FIGS. 1 to 3disposed for guiding roving or sliver to one pair of co-operatingdrafting rollers 2, 2 is formed by a pair of co-operating guide rollers3, 3 rotatably mounted on upright pins 4, 4 carried by a support bracket5. This bracket 5 is secured to the traverse rod 6 of a textile fibredrafting mechanism so that the axes of rotation of the guide rollers 3,3 are at right-angles to the axes of rotation of the drafting rollers 2,2, and the nip between the guide rollers 3, 3 immediately precedes theintake to the drafting mechanism constituted by the nip between thedrafting rollers 2, 2. On the side of the nip between the guide rollers3, 3 remote from the drafting rollers 2, 2 there is a further guideformed by a funnel 7 (not shown in FIG. 3) disposed for guiding rovingor sliver into the nip between the guide rollers 3, 3. The funnel 7 iscarried by a bracket 8 that is fast with the traverse rod 6. In modifiedforms, not shown, the guide rollers 3, 3 are supported for rotationabout axes parallel with the axes of rotation of the drafting rollers 2,2 or for rotation about axes inclined with respect to the axes ofrotation of the drafting rollers 2, 2.

In use of the first form of guide, textile fibres formed as roving orsliver drawn into the drafting mechanism by the drafting rollers 2, 2which are driven, pass to the rollers 2, 2 via the funnel 7 and the nipbetween the guide rollers 3, 3. The guide rollers 3, 3 are urged towardsone another, preferably resiliently, by a mechanism, not shown, so thatthe nip therebetween forms a confined passage through which the fibresare fed, whereby the fibres experience a resistance to their movementthrough the nip between the guide rollers 3, 3 and hence are paid outfrom this nip under tension. The mechanism urging the guide rollers 3, 3towards one another can be overridden so that these rollers can be movedapart to facilitate insertion of the roving or sliver at thecommencement of operation. The passage of the roving or sliver betweenthe guide rollers 3, 3 causes these rollers to rotate and hence thecurved surfaces of these rollers form co-operating guide surfaces thatmove along with the fibres confined therebetween. A mechanism (notshown) may be provided for braking the rotational movement of the guiderollers 3, 3 so that the amount of resistance offered to the passage ofthe fibres can be selected. Furthermore the guiding surfaces of therollers 3, 3 may be patterned in any desired way so as to facilitatepositive engagement with the roving or sliver and minimize the risk ofslipping.

It will be appreciated that the configuration of the funnel 7 is such asnot to restrain the fibre strands to any substantial degree.

The second form of roving or sliver guide 1A shown in FIGS. 4 and 5disposed for guiding roving or sliver 9 to one pair of co-operatingdrafting rollers 2, 2 includes a pair of co-operating elongated guidesulfaces constituted by co-operating runs of two flexible idler endlessbands 10, 10 which are mounted so as to be capable of revolving aroundsupport blocks 11. These support blocks 11 for the bands 10 arethemselves mounted in a stationary position and at a location such thatthe co-operating band runs extend parallel to the fibre feed path andover an appreciable length of the path up to a delivery point whichclosely precedes the nip between the pair of drafting rollers 2, 2. Thelength of the co-operating band runs will, of course, depend upon thesize of the bands 10, 10 employed and the form of the support blocks 11,but are normally chosen so as to provide a confining path of appreciablelength for the fibres.

Displacement of the co-operating band runs, and thus also rotation ofthe bands 10, 10 around their support blocks 11, is brought about by theaction of the sliver or roving 9 which passes between the band runs andis itself progressively drawn into the nip between the pair of draftingrollers 2, 2, which are driven as already mentioned. This arrangementtends to ensure that just the right amount of sliver or roving 9 is paidout from the guide 1A. For best results, the two bands 10 must offer asubstantial degree of resistance to turning so that the fibre strandswill enter the nip of the drafting rollers 32 in a taut condition andconsequently at as uniform a rate as is possible. The facing surfaces ofthe co-operating band runs may also be patterned in any desired way soas to ensure a positive engagement with the fibre strands therebytending to eliminate the risk of slipping.

Different degrees of grip upon fibre strands passing between theco-operating band runs, and a frictional resistance to movement of thebands 10 themselves, can be obtained in various ways. Thus, for example,bands 10 of different thicknesses may be employed or the size and shapeof the band support blocks 11 may be varied. In the first modified formof guide 1A shown in FIG. 6 resistance to band movement is regulated bysupplying different shapes or sizes of additional support elements 12that can be selectively mounted within the forward ends of the bandloops. In the second modified form of guide 1A" shown in FIG. 7resistance to band movement is regulated by providing a band supportblock 11A with an angularly adjustable member 13 which can be caused toexert varying pressures on the inside surface of the return run of theassociated band 10. In yet another arrangement (not shown), instead ofproviding for frictional resistance to band turning between the bandsand their support blocks, the blocks are mounted to revolve and arebraked in any desired manner to provide the necessary retarding actionon the fibre strands being drawn between the band runs. In a furtherarrangement, not shown, brake means is applied to the edges of the bandsthemselves.

With all the forms of guide employing band runs a wide fork guide orvery loose round guide may be arranged to precede the intake end of theco-operating band runs, merely to coax the sliver or roving into thebands without constraining the fibre strands to any substantial degree.

Any of the forms of guide that have been described can be covered in anysuitable way to prevent the ingress of fly or dust.

I claim:

1. A method of guiding sliver to the feed rolls of a drafting mechanism,said method comprising drawing the sliver from the outlet of a funnel bysaid feed rolls, interposing idler guiding surfaces between said funneland said feed rolls, receiving the sliver at the idler guiding surfacesfrom the outlet of the funnel such that the sliver progressively passesfrom the funnel to the guiding surfaces and then to the feed rolls ofthe drafting mechanism, guiding the sliver with said guiding surfaceswhile applying prescribed resistance to the sliver by said guidingsurfaces, moving the guiding surfaces under the drawing action of thesliver and discharging the sliver from said guiding surfaces throughsaid feed rolls and directly into said drafting mechanism withsubstantially no travel between the guiding surfaces and the feed rolls.

2. Apparatus for guiding sliver to the feed rolls of a draftingmechanism, said apparatus comprising a guide member with an outlet forthe supply of sliver to be fed to said drafting mechanism, guide meansfor receiving the sliver from said guide member and for guiding thesliver to said drafting mechanism, drawing means including said feedrolls for pulling the sliver through said guide means, said guide meansbeing interposed between the outlet of said guide member and saiddrawing means, said guide means having opposed freely movablecooperating guide surfaces defining therebetween a confined passagewaythrough which the sliver passes from the outlet of said guide member tothe feed rolls of the drafting mechanism, and means supporting saidguide surfaces for travel with and under the action of the sliver whilethe surfaces offer prescribed resistance to the travel of the sliver.

3. Apparatus as claimed in claim 2, wherein at least one of saidsurfaces is round and constituted by a roller.

4. Apparatus as claimed in claim 2, wherein at least one of saidsurfaces is fiat and constituted by a belt.

5. Apparatus as claimed in claim 2, wherein said means supporting saidguide surfaces further comprises means for applying frictionalresistance to said guide surfaces to oppose advancement thereof with thesliver.

6. Apparatus as claimed in claim 2, wherein said guide means comprises apair of cooperating rollers defining a nip therebetween whichconstitutes said confined passageway, said cooperating guide surfacesbeing formed by the curved surfaces of said rollers; said rollers beingsupported for rotation by the action of the sliver drawn through saidnip by said drawing means, so that said curved surfaces move along withthe sliver confined therebetween, and resist movement of the sliverthrough said nip whereby the sliver is paid out from said nip undertension.

7. Apparatus as claimed in claim 2, wherein said guide means comprises apair of belts having cooperating runs, said cooperating guide surfacesbeing formed by the adjacent surfaces of said cooperating runs, saidruns extending along the path along which said sliver is fed to saidfeed rolls to form said confined passageway, said belts being supportedfor movement along said path by the action of the sliver drawntherebetween by said drawing means, so that said runs move along withthe sliver confined therebetween, and resist movement of the sliverwhereby the sliver is paid out from between said runs under tension.

8. Apparatus as claimed in claim 7 comprising means 6 for applyingbraking movement to said runs along said feed path.

9. Apparatus as claimed in claim 7, wherein said means supporting saidguide surfaces comprises a plurality of support elements differing inshape and size from one another about which each of said belts ispassed.

10. Apparatus as claimed in claim 7, wherein said means supporting saidguide surfaces comprises a member associated with each belt and aroundwhich each belt is passed, which member is adjustable in extent toeffect variable braking of the movement of the belt.

11. Apparatus as claimed in. claim 2, wherein said guide member is afunnel urging the sliver to enter between said cooperating guidesurfaces without itself constraining the sliver to any substantialdegree.

References Cited UNITED STATES PATENTS 2,025,394 12/ 1935 Langen 19288X3,067,471 12/1962 Noda 19243 3,417,436 12/1968 Masurel 19258 2,328,8999/ 1943 Goodspeed 19-2'86 2,624,074 1/1953 Watson 19-286 3,020,697 2/1962 Henry 19-288 DORSEY NEWTON, Primary Examiner

